A variety of approaches to optical imaging and analysis have been used for many different applications. For example, the endoscope is a useful tool for a variety of applications such as biological research, medical diagnostics, and for image guidance in surgical procedures. Conventional endoscopes utilize a white light source to illuminate a sample and reflected light to visualize the same sample. Such conventional endoscopes are typically limited, however, to visualizing the surface of a sample or to surface inspection within a hollow tissue cavity.
Certain types of optical analysis approaches are discussed in connection with the following patent documents: U.S. Pat. Nos. 6,485,413 and 6,423,956, and U.S. Patent application Publication Number US 2003/0142934.
Many applications for which optical analysis would be beneficial are subject to a variety of limitations to such analysis. For example, space constraints in many applications limit the use of certain tools that are not generally scaleable in a manner that would facilitate such tools' use for these applications. In addition, while certain tools have been useful in applications characterized by small space constraints, these tools are often limited in their ability to achieve desirable results, or by their ability for use with certain samples such as biological samples that may include live beings. Furthermore, many optical analysis approaches are limited to the analysis of linear optics.
Some applications benefit from subcutaneous analysis, in particular with a specimen. However, invasive analysis of a specimen can be challenging, particularly when the analysis is to be made over time. For example, when a subcutaneous area of a living specimen is to be accessed multiple times, processes used to facilitate the access must be repeated. In addition, each time a specimen is accessed subcutaneously, infection and other medical complications can arise.
The above and other issues have presented challenges to optical analysis approaches and, in particular, to optical imaging in applications exhibiting relatively small space such as for endoscopic and microscopic applications.